1. Field
The present invention relates to an optical disc drive. More specifically, the present invention relates to a slim type optical disc drive making use of low cost flexible flat cable (FFC) which can be mass-produced according to the corresponding standard specifications.
2. Discussion of the Related Art
Optical disc drives (ODDs) are in wide use today, which record data such as audio, video, and text to or play the data from various types of optical discs such as CDs, DVDs, and BDs.
Notebook computers are usually equipped with a slim-type optical disc drive; as shown in FIG. 1, the slim-type optical disc drive may employ a flexible printed cable (FPC) or a flexible flat cable (FFC) to be connect to a SATA connector which is connected mechanically to a notebook computer and a moving tray.
The flexible printed cable (FPC) has an advantage of allowing conductor specifications such as length, width, and so on to be chosen arbitrarily during cable design for adjusting impedance of the cable but incurs high manufacturing costs; meanwhile, the flexible flat cable (FFC) can be mass-produced according to the corresponding standard specifications, thus allowing low manufacturing costs but provides only a few design choices for conductor specifications such as length, width, and so on to adjust impedance of the cable.
For example, as shown in FIG. 1, the conductor of flexible flat cable (FFC) in wide use has been standardized such that W (width)=0.32 mm, H (height)=0.028 mm, P (pitch)=0.5 mm, and so on; therefore, as shown in FIG. 2, in case of using a flexible flat cable (FFC) 30 between the SATA connector 11 installed at the inner, rear surface of the lower case 10 of a slim-type optical disc drive 100 and the PCB connector 22 installed at the printed circuit board (PCB) 21 of the rear surface of the tray 20, impedance matching required for SATA interface designed for fast data transfer is difficult to accomplish.
In other words, in case of using a flexible flat cable 30 manufactured with the specifications that W (width)=0.32 mm, H (height)=0.028 mm, and P (pitch)=0.5 mm, the cable has an impedance value ranging 135 to 140 ohm; meanwhile, since SATA interface requires an impedance value ranging 85 to 115 ohm, if the flexible flat cable 30 is used to connect the SATA connector 11 and the PCB connector 22, an error may occur during fast data transfer employing the SATA interface due to impedance mismatching.